1. Field of the Invention
The present invention relates generally to medical and surgical devices, and more specifically to catheter assemblies.
2. Description of Prior Art and Related Information
Catheter assemblies are generally inserted through body conduits to provide access to body cavities so as to enable medical procedures to be performed less invasively. In certain procedures, such as surgery or drainage, it is necessary for the catheter to be temporarily anchored in the body cavity to allow the desired procedure to be completed.
Different mechanisms have been provided for the purpose of deploying a catheter within a body cavity in order to prevent withdrawal during a procedure. One example includes an inflatable balloon disposed on the tip of a catheter. Once the tip is within the body cavity, the balloon is inflated through an inflation lumen running through the shaft of the catheter. The presence of the inflation lumen, however, increases the necessary diameter of the shaft which must also accommodate a second lumen intended for the desired procedure, such as a drainage lumen.
A larger catheter diameter, however, increases discomfort. While decreasing the diameter of the inflation lumen may contribute to a slightly smaller overall diameter of the catheter, an inflation lumen with a small diameter is more likely to develop kinks in the passageway, obstructing the flow of fluid necessary to inflate and deflate the balloon.
Conventional balloons are not liquid permeable. In drainage procedures, therefore, ports must be provided in the shaft at a location outside of the balloon. In typical catheters where ports are disposed on the shaft proximate to the balloon, a greater length of the catheter must be inserted into the body cavity in order to provide fluid communication between the ports and the liquid within the cavity. This greater xe2x80x9cstack profilexe2x80x9d increases discomfort. Furthermore, particular body cavities can only accommodate a-certain length of catheter. Therefore, limited room is available for the placement of ports on the shaft, which leads to a small overall area for drainage. This smaller area contributes to excessive residual liquid remaining in the body cavity which may lead to infections and other complications.
Conventional catheters, including balloon catheters, must be manually deployed. Thus, an operator must gauge when the tip portion of the catheter, including the balloon, is sufficiently within the target body cavity in order to initiate inflation. Predilation, resulting in severe trauma to the patient, can occur if the deploying device, such as a balloon, is prematurely expanded in the narrow body conduit connected to the cavity.
The removal of conventional catheters is also problematic because manual manipulation is required. A typical anchor, such as a balloon, deployed in the body conduit is configured in its expanded, high-profile state. Before the catheter may be withdrawn, the conventional anchor must be manually returned to its low-profile state so that it may re-enter the narrow body conduit. Various mechanisms are provided in the prior art for manually converting the anchor from its high-profile state to its low-profile state. One existing method includes inserting a stylet through the catheter to push the distal tip out in order to form the low-profile state. The necessity for manual manipulation in conventional assemblies increases time, effort, expense and inconvenience in withdrawing a catheter.
The present invention provides structures and methods which overcome the deficiencies of the prior art.
In one aspect, a method is provided for inserting a medical instrument through a body conduit and for anchoring the medical instrument in a body cavity. The method comprises the steps of providing an elongate tube having a shaft proximal end and a shaft distal end, affixing a stop along the tube at an anchoring position, forming an anchoring device with an anchor proximal end and an anchor distal end, providing the anchoring device with characteristics including a high-profile state when the anchor proximal end and the anchor distal end are in a generally proximate relationship, and a low-profile state when the anchor proximal end and the anchor distal end are in a generally spaced relationship, and mounting the anchoring device relative to the tube with the anchor distal end movable between a distal end proximal position distal of the stop and a distal end distal position, and with the anchor proximal end movable between a proximal end proximal position and a proximal end distal position proximal of the stop.
The method also comprises the steps of inserting the tube into the body conduit toward the body cavity, and during the inserting step, moving the anchor proximal end to the proximal end proximal position with the anchor distal end at the distal end proximal position to maintain the anchoring device in the low-profile state. The method further comprises the steps of positioning the tube with the stop in the body cavity, and withdrawing the tube sufficiently to move the anchor proximal end to the proximal end distal position and to provide the anchoring device with its high profile characteristics.
The step of withdrawing the tube comprises the step of moving the anchor proximal end to the proximal end distal position within the body cavity. The method further comprises the step of releasably locking the distal end of the anchoring device in the distal end proximal position, retracting the shaft from the body cavity, during the retracting step, releasing the anchor distal end from the distal end proximate position; and, after the releasing step, moving the anchor distal end to the distal end distal position to space the anchor distal end from the anchor proximal end so as to provide the anchoring device with its low-profile characteristics during the retracting step.
The releasably locking step comprises the step of coupling the anchor distal end to a suture engaged in a proximal direction. The releasing step comprises the step of disengaging the suture from the proximal direction. The step of forming an anchoring device comprises the step of forming a bulb, the step of forming a hinged wing structure, or the step of forming a spiral. The method further comprises the step of draining fluid from the body cavity with the anchoring device and the tube.
In another aspect, a method is also provided for inserting a catheter assembly through a body conduit and automatically deploying the assembly into a body cavity. The method comprises the steps of coupling an anchoring device with an anchor proximal end and an anchor distal end to a tube, providing the anchoring device with characteristics ranging between a high-profile state when the anchor proximal end and the anchor distal end are in a generally proximate relationship, and a low-profile state when the anchor proximal end and the anchor distal end are in a generally spaced relationship, disposing a stop on the tube between the anchor proximal end and the anchor distal end, automatically forming the low-profile state upon inserting the anchoring device into the body cavity, and automatically forming the high-profile state upon withdrawing the tube with the anchoring device disposed in the body cavity.
The step of automatically forming the low-profile state comprises the step of forming the low-profile state only by inserting the tube in a distal direction. The step of automatically forming the high-profile state comprises the step of forming the high-profile state only by moving the tube in a proximal direction once the anchoring device is disposed in the body conduit without any manual manipulation of the anchoring device.
Once the anchor distal end is disposed in the body cavity, the method further comprises the step of moving the anchor distal end from a distal end proximal position adjacent to the stop to a distal end distal position further from the stop to facilitate a low-profile state for removal of the anchoring device. The step of moving the anchor distal end from the distal end proximal position to the distal end distal position comprises the step of releasing a lock adapted to hold the anchor distal end in the distal end proximal position.
An anchor assembly movable with a medical device through a body conduit is provided for anchoring the medical device in a body cavity. The assembly comprises an elongate tube associated with the medical device and having a shaft proximal end and a shaft distal end, a stop fixed to the tube generally at a position desired for anchoring the tube, an anchoring device carried by the tube and having an anchor distal end distal of the stop, and an anchor proximal end proximal of the stop. The distal end of the anchoring device is movable between a distal end proximal position and a distal end distal position. The anchor proximal end is movable between a proximal end proximal position and a proximal end distal position. The assembly also includes a lock operable from the shaft proximal end to hold the anchor distal end in the distal end proximal position to facilitate insertion in the low-profile state and anchoring in the high-profile state. The lock is operable to release the anchor distal end from the distal end proximal position to facilitate withdrawal of the medical instrument with the anchoring device in the low-profile state.
In a preferred embodiment, the anchoring device comprises a bulb composed of a liquid permeable material. The tube comprises apertures disposed at a position between the proximal end and the distal end of the anchoring device.
In a further aspect, a self-deployable catheter assembly is provided. The assembly comprises a tube with a shaft proximal end and a shaft distal end, a stop fixed to the tube at a stop position between the shaft proximal end and the shaft distal end, an anchoring device carried by the tube, and a releasable lock operable to hold the anchor distal end in a distal end proximal position to facilitate insertion in the low-profile state and anchoring in the high-profile state. The anchoring device has an anchor distal end distal of the stop, and an anchor proximal end proximal of the stop. The anchoring device is movable between a low-profile state and a high-profile state. The lock is operable to release the anchor distal end from the distal end proximal position to facilitate withdrawal in the low-profile state.
The anchoring device may comprise a bulb, a hinged wing structure, a spiral, or any other structure that is interchangeable between an expanded, high-profile state and a narrow, low-profile state.
The anchor proximal end is freely movable between a proximal end distal position adjacent to the stop, and a proximal end proximal position spaced apart from the stop. A slide is coupled to the anchor proximal end. A slidable bushing or cap is coupled to the anchor distal end. The releasable lock preferably comprises a suture.
In a further aspect, a catheter assembly is provided, comprising a tube; and an anchoring device mounted to the tube. The anchoring device has an anchor distal end held in a fixed position by a releasable lock and an anchor proximal end freely movable between a proximal end proximal position and a proximal end distal position. The proximal end distal position is defined by a stop disposed on the tube between the anchor distal end and the anchor proximal end. The anchoring device has a high-profile state when the anchor distal end and the anchor proximal end are in a generally proximate relationship, and a low-profile state when the anchor distal end and the anchor proximal end are in a generally spaced relationship. The distal end is movable to a released position distal of the fixed position upon releasing the lock. The anchoring device may be liquid permeable. The tube comprises apertures disposed between the anchor proximal end and the anchor distal end.
In all of the above disclosed embodiments, it will be noted that an anchoring device comprises both an anchor distal end and an anchor proximal end, the proximity of which determine whether the anchoring device has a high or low profile. Thus, these opposed ends facilitate both a high-profile state when close together in a proximate relationship, and a low-profile state when spaced further apart in a spaced relationship. It will further be noted that the anchor distal end is held in a distal end proximal position by a releasable lock that is operative from the time the catheter is manufactured until the time the lock is released. Once the lock is released, the anchor distal end is movable to the distal end distal position.
In summary, a self-deploying catheter assembly comprises an anchoring device mounted to a tube. A distal end of the anchoring device is held in a fixed position by a releasable suture while a proximal end is freely movable between a proximal position and a distal position defined by a stop on the tube. During insertion into a body cavity, the anchor automatically maintains a low-profile state with the ends spaced apart. Once fully inserted, the anchor self converts into a high-profile state when the tube is slightly withdrawn, bringing the ends closer together. The suture is disengaged to release the distal end of the anchor in order to facilitate a low-profile state for withdrawal of the assembly.
The invention, now having been briefly summarized, may be better appreciated by the following description of preferred embodiments and reference to the associated drawings.